diff --git a/openbsc/src/bsc_api.c b/openbsc/src/bsc_api.c
index c8ef4f4..0dcb72b 100644
--- a/openbsc/src/bsc_api.c
+++ b/openbsc/src/bsc_api.c
@@ -317,7 +317,7 @@
 }
 
 int gsm0808_cipher_mode(struct gsm_subscriber_connection *conn, int cipher,
-			uint8_t *key, int len)
+			const uint8_t *key, int len, int include_imeisv)
 {
 	return -1;
 }